Noise Level Zero, variously NLZero or just NLZ, is a new moderated textual conferencing system similar to, and largely composed of the former online community of, BIX. BIX finally went dark in June 2001. Like BIX, The WELL, and others, the primary feature of NLZero is a collection of conferences, or threaded conversations, on a wide variety of topics. Its web site claims discussion on "PCs, databases, cars, airplanes, politics in Croatia, or almost anything imaginable", and that its volunteer moderation ensures a noise to signal ratio of zero.

After it became clear that Delphi was no longer interested in continuing to operate the BIX service, the hardcore users of the system, led in part by longtime member John Ralls, determined to save their community by migrating to a new system not under the control of an indifferent corporation.

One significant victory for for the bixen came in the spring of 2001, when they convinced the University of Guelph and CSP Internet to release CoSy under the GPL. CoSy, originally written in 1984 by Alastair Mayer at Guelph for a defunct company called Softwords, was the software behind BIX for its entire 16-year existence, as well as CIX, a similar European system, and others. That software is now hosted at Sourceforge, both in its original 1984 form, and as a current release.

Thanks to the use of BIX's old software platform, NLZero both shares BIX's text interface for telnet/ssh users and interoperates with Galahad, a Windows GUI for the service. Graphical front ends for other operating systems are also available. In addition, NLZero has an NNTP server so that its discussions can be accessed from a usenet newsreader.

The web site of Noise Level Zero discusses BIX's demise.
CoSy (Conference System) is the software running NLZero.
The home page of Alastair Mayer, original author of CoSy.